http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55980
Bug #: 55980
Summary: missed optimizations with internal_pack
Classification: Unclassified
Product: gcc
Version: 4.8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: ja...@gcc.gnu.org
This is a tracking bug for possible remaining problems of PR 55072:
-------------------------------------------------------------------
1) In PR 55072 comment 13, Mikael writes about this patchlet:
> Index: gcc/fortran/trans-array.c
> ===================================================================
> --- gcc/fortran/trans-array.c (revision 194517)
> +++ gcc/fortran/trans-array.c (working copy)
> @@ -6995,20 +6995,14 @@ gfc_conv_array_parameter (gfc_se * se, gfc_expr *
> this_array_result = false;
>
> /* Passing address of the array if it is not pointer or assumed-shape. */
> - if (full_array_var && g77 && !this_array_result)
> + if (full_array_var && g77 && !this_array_result
> + && sym->ts.type != BT_DERIVED && sym->ts.type != BT_CLASS)
> {
> tmp = gfc_get_symbol_decl (sym);
It feels like a hack (that what there before) to blindly disable derived types
here. The real problem is that the code under the if condition supports only
bare variables without subreferences.
On the other hand it looks like a correct hack WRT the existing behaviour.
-------------------------------------------------------------------
2) In http://gcc.gnu.org/ml/fortran/2012-12/msg00098.html, Tobias writes:
"Without experimenting more carefully, I have the gut feeling that there are
still cases where we might end up with invalid code and there is missed
optimization." [For more details see his full post.]
-------------------------------------------------------------------
3) In http://gcc.gnu.org/ml/fortran/2013-01/msg00091.html, Mikael writes:
For:
>>> @@ -6995,20 +6995,14 @@ gfc_conv_array_parameter (gfc_se * se, gfc_expr *
>>> this_array_result = false;
>>> /* Passing address of the array if it is not pointer or
>>> assumed-shape. */
>>> - if (full_array_var&& g77&& !this_array_result)
>>> + if (full_array_var&& g77&& !this_array_result
>>> +&& sym->ts.type != BT_DERIVED&& sym->ts.type != BT_CLASS)
I would have used instead:
&& expr->expr_type == EXPR_VARIABLE && ref == NULL)
to make the optimization available to variables of derived type.
